Saturday, December 13, 2014

Safety glass is made by treating a glass especially so that it does not break easily. Even if a safety glass shatters, it remains safe. The safety glass has been made because of the growing need of security at various places like automobiles, for cooking, law enforcement, etc. It has been in use since 1927, when it was used as windshields in automobiles. Safety glass is also used in industrial work and for construction.

There are two kinds of safety glass: Tempered and

Tempered Glass

This kind of glass is made by a process known as tempering. The glass is made many times harder by heating it and immediately cooling it off. When this process is repeated several times, the molecular structure of the glass is altered and the glass becomes harder. The process of tempering is also used to make the glass more brittle. This is done so that the entire shatters all at once if the external force applied on it is powerful enough.

One of the most important characteristic features of tempered is that it does not break into sharp or jagged pieces when it shatters. The tempered glass breaks into pieces that resemble cubes or stones. The broken pieces of tempered are not heavy enough to cut the skin.

The tempered is used in the windows of cars. Being heat resistant, is used in coffee makers, ovens and even as computer screens.

Laminated Glass

Laminated glass is a type of safety glass that holds together when shattered. In the event of breaking, it is held in place by an interlayer, typically of polyvinyl butyral (PVB), between its two or more layers of glass. The interlayer keeps the layers of glass bonded even when broken, and its high strength prevents the glass from breaking up into large sharp pieces. This produces a characteristic "spider web" cracking pattern when the impact is not enough to completely pierce the glass.

Laminated glass is normally used when there is a possibility of human impact or where the glass could fall if shattered. Skylight glazing and automobile windshields typically use laminated glass. In geographical areas requiring hurricane-resistant construction, laminated glass is often used in exterior storefronts, curtain walls and windows. The PVB interlayer also gives the glass a much higher sound insulation rating, due to the damping effect, and also blocks 99% of incoming UV radiation.